Honeycomb panels with one layer of hexagonally shaped cells sandwiched between backing sheets are known. One use is as side protection/impact force absorbing elements in the doors of vehicles. These panels are e.g. made of paper which provides a cheap, simple and light construction. The problem is to achieve a door construction which on one hand can absorb a high proportion of the energy released in a collision and, on the other hand, does not add too much weight and cost to the vehicle. The known honeycomb panels do not have sufficient impact absorbing capacity for this use neither can their impact absorbing capacity be varied.